Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Development of Chemometrics Method Based on Infrared Spectroscopy for the Determination of Cement Composition and Process Optimization [article](ACG Publications, 2022) Özdemir, Durmuş; Gümüş, Mehmet Gökhan; Tepeli, DilekIn combination with a multivariate calibration method, FTIR-ATR spectroscopy was presented as a rapid method for the determination of some major oxides (CaO, SiO2, Al2O3, Fe2O3) and minor oxides (MgO, SO4, Na2O, and K2O) in diverse materials (raw material, raw meal, additives, clinker, and types of cement) in cement manufacturing. The FTIR spectroscopy based multivariate models were generated by taking X-ray fluorescence (XRF) as a reference method. Among a number of spectral preprocessing methods, extended multiplicative scatter correction (EMSC) yielded the best PLS models. The standard error of prediction (SEP) for the optimal FTIR based PLS models ranged from 0.10 to 2.07 (w/w%), and the regression coefficient (R2) ranged from 0.95 to 0.99 for PLS predicted vs XRF reference plots. Statistical evaluation of the both methods was carried out by paired t-test at the 95% confidence level and the results showed that the FTIR-ATR combined with PLS model results are consistent with the XRF reference measurements for all the oxides studied. Compared to the XRF method, which can take anywhere from a few minutes to an hour for each measurement, the proposed method is faster, cheaper, and safer. The presented technology also allows rapid monitoring of a cement factory production line.Article Citation - WoS: 9Citation - Scopus: 11Prediction of Vinegar Processing Parameters With Chemometric Modelling of Spectroscopic Data(Elsevier, 2021) Çavdaroğlu, Çağrı; Çavdaroğlu, Çağrı; Özen, Banu; Özen, Fatma BanuSpectroscopic methods have the advantages of being rapid and environmentally friendly and can be used in measurement and control of processing parameters during food production. It was aimed to predict several quality and chemical parameters of vinegar processing from UV-visible and mid-infrared spectroscopic profiles. Two processing lines of both traditional and submerged vinegar production from 2 separate grape varieties (green and red grapes) were monitored. Some of the important markers of the fermentation processes; pH, brix, total acidity, total flavonoid content, total and individual phenolic contents, organic acid, sugar, ethanol concentrations as well as UV-visible and mid-infrared spectra were obtained during both types of vinegar processing and quality and chemical parameters were predicted from spectroscopic data using chemometric methods. Individual UV-visible and mid-infrared spectral profiles along with low level of data fusion were used in building of chemometric prediction models. Accurate, reliable and robust prediction models (R(2)cal and R(2)val >0.9) were obtained for quality parameters mostly with combination of two spectroscopic datasets. Predictive models used for phenolic components were below average except for p-coumaric and syringic acids. Citric and acetic acids were the most accurately estimated ones among organic acids along with ethanol. Close agreements between reference and predicted values were obtained during the monitoring of changes of some quality parameters for vinegar fermentation process through rapid and simultaneous spectroscopic measurements.Article Citation - WoS: 3Citation - Scopus: 4Comparison of the Effects of Statins on A549 Nonsmall-Cell Lung Cancer Cell Line Lipids Using Fourier Transform Infrared Spectroscopy: Rosuvastatin Stands Out(Wiley, 2021) Aksoy, Hatice Nurdan; Ceylan, ÇağatayStatins are commonly prescribed antilipidemic and anticholesterol class of drugs. In addition to their major role, they have been found to have anticancer effects on in vitro, animal and clinical studies. The aim of this study was to investigate the effects of six different statins (rosuvastatin, pravastatin, simvastatin, lovastatin, fluvastatin, and atorvastatin) on A549 cancer cells lipids by Fourier transform infrared (FTIR) spectroscopy. Proliferation tests were carried out to detect the half-maximal inhibitory concentrations (IC50) of each statin on A549 cells. The IC50 values were 50 mu M for simvastatin, 150 mu M for atorvastatin and pravastatin, and 170 mu M for fluvastatin, 200 mu M for rosuvastatin and lovastatin on A549 cells. No correlation was found between the antiproliferative effects of the statins and lipid-lowering effect. The cells were treated with IC5, IC10, and IC50 values of each statins concentration and lipid extracts were compared using FTIR spectroscopy. The results indicated that different statins had different effects on the lipid content of A549 cells. The FTIR spectra of the lipid exctracts of statin-treated A549 cells indicated that the value of hydrocarbon chain length, unsaturation index, oxidative stress level, and phospholipid containing lipids increased except for rosuvastatin-treated A549 cells. In addition, rosuvastatin significantly lowered cholesterol ester levels. In conclusion, the contrasting effects of rosuvastatin should be further investigated.Article Citation - WoS: 23Citation - Scopus: 23Cold Sintering of Soda-Lime Glass(Elsevier Ltd., 2021) Karacasulu, Levent; Ögür, Ezgi; Pişkin, Cerem; Vakıfahmetoğlu, ÇekdarOrdinary recycled soda lime glass powder was densified via cold sintering process with the aid of concentrated NaOH solution. Increase in processing time, temperature and concentration of the NaOH solution resulted in the formation of monolithic glass artifacts with higher relative densities. The sample densified the most (95.2%) was obtained when the sintering was performed at 250˚C with a 20 min dwell time using 15 M NaOH solution.Article Citation - WoS: 2Citation - Scopus: 3Comparision of in Situ Spectroscopic Ellipsometer and Ex Situ X-Ray Photoelectron Spectroscopy Depth Profiling Analysis of Hfo2/Hf Multilayer Structure(IOP Publishing Ltd., 2018) Cantaş, Ayten; Özyüzer, Lütfi; Aygün, GülnurA HfO2 film was grown by RF magnetron sputtering technique on a Si substrate Using in situ Spectroscopic Ellipsometry (SE), the film thickness and refractive index were examined as a function of deposition time. Ex situ x-ray Photoelectron Spectroscopy (XPS) was used in depth profile mode to determine the phase evolution of HfO2/Hf/Si multilayer structure after the growth process. The chemical composition and the crystal structure of the film were investigated by Fourier Transform Infrared (FTIR) spectroscopic measurements and x-ray Diffraction in Grazing Incidence (GI-XRD) mode, respectively. The results showed that the film was grown in the form of HfO2 film. According to SE analysis, reactive deposition of HfO2 directly on Hf/Si results to SiO2 interface of about 2 nm. The final HfO2 films thickness is 5.4 nm. After a certain period of time, the XPS depth profile revealed that the film was in the form of Hf-rich Hf silicate with SiO2 interfacial layer. In reference to XPS quantification analysis from top to bottom of film, the atomic concentration of Hf element reduces from 19.35% to 7.13%, whereas Si concentration increases from 22.99% to 74.89%. The phase change of HfO2 film with time is discussed in details.Article Citation - WoS: 6Citation - Scopus: 6A Molecular and Biophysical Comparison of Macromolecular Changes in Imatinib-Sensitive and Imatinib-Resistant K562 Cells Exposed To Ponatinib(SAGE Publications Inc., 2016) Kartal Yandım, Melis; Ceylan, Çağatay; Elmas, Efe; Baran, YusufChronic myeloid leukemia (CML) is a type of hematological malignancy that is characterized by the generation of Philadelphia chromosome encoding BCR/ABL oncoprotein. Tyrosine kinase inhibitors (TKIs), imatinib, nilotinib, and dasatinib, are used for the frontline therapy of CML. Development of resistance against these TKIs in the patients bearing T315I mutation is a major obstacle in CML therapy. Ponatinib, the third-generation TKI, is novel drug that is effective even in CML patients with T315I mutation. The exact mechanism of ponatinib in CML has been still unknown. In this study, we aimed to determine the potential mechanisms and structural metabolic changes activated by ponatinib treatment in imatinib-sensitive K562 human CML cell lines and 3 μM-imatinib-resistant K562/IMA3 CML cell lines generated at our lab. Apoptotic and antiproliferative effects of ponatinib on imatinib-sensitive and 3 μM-imatinib-resistant K562/IMA3 CML cells were determined by proliferation and apoptosis assays. Additionally, the effects of ponatinib on macromolecules and lipid profiles were also analyzed using Fourier transform infrared spectroscopy (FTIR). Our results revealed that ponatinib inhibited cell proliferation and induced apoptosis as determined by loss of mitochondrial membrane potential, increased caspase-3 enzyme activity, and transfer of phosphatidylserine to the plasma membrane in both K562 and K562/IMA-3 cells. Furthermore, cell cycle analyses revealed that ponatinib arrested K562 and K562/IMA-3 cells at G1 phase. Moreover, ponatinib treatment created a more ordered nucleic acid structure in the resistant cells. Although the lipid to protein ratio increased in imatinib-sensitive K562 cells with a little decrease in the K562/IMA-3 cells, ponatinib treatment indicated significant changes in the lipid composition such as a significant increase in the cellular cholesterol amounts much more in the K562/IMA-3 cells than the sensitive counterparts. Unsaturation in lipids was higher in the resistant cells; however, increases in lipids without phosphate and the number of acyl chains were much higher in the K562 cells. Taken together, all these results showed powerful antiproliferative and apoptotic effects of ponatinib in both imatinib-sensitive and imatinib-resistant CML cells in a dose-dependent manner, and hence, the use of ponatinib for the treatment of TKI-resistant CML patients may be an effective treatment approach in the clinic. More importantly, these results showed that FTIR spectroscopy can detect drug-induced physiological changes in cancer drug resistance.Article Citation - WoS: 16Citation - Scopus: 38Time-Dependent Physicochemical Characteristics of Malaysian Residual Soil Stabilized With Magnesium Chloride Solution(Springer Verlag, 2016) Latifi, Nima; Rashid, Ahmad Safuan A.; Ecemiş, Nurhan; Tahir, Mahmood Md; Marto, AminatonThe effects of non-traditional additives on the geotechnical properties of tropical soils have been the subject of investigation in recent years. This study investigates the strength development and micro-structural characteristics of tropical residual soil stabilized with magnesium chloride (MgCl2) solution. Unconfined compression strength (UCS) and standard direct shear tests were used to assess the strength and shear properties of the stabilized soil. In addition, the micro-structural characteristics of untreated and stabilized soil were discussed using various spectroscopic and microscopic techniques such as X-ray diffractometry (XRD), energy-dispersive X-ray spectrometry (EDAX), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR) and Brunauer, Emmett and Teller (BET) surface area analysis. From the engineering point of view, the results indicated that the strength of MgCl2-stabilized soil improved noticeably. The degree of improvement was approximately two times stronger than natural soil after a 7-day curing period. The results also concluded the use of 5 % of MgCl2 by dry weight of soil as the optimum amount for stabilization of the selected soil. In addition, the micro-structural study revealed that the stabilization process modified the porous network of the soil. The pores of the soils had been filled by the newly formed crystalline compounds known as magnesium aluminate hydrate (M-A-H).Article Citation - WoS: 24Citation - Scopus: 25Investigation of the Structure of Alpha-Lactalbumin Protein Nanotubes Using Optical Spectroscopy(Cambridge University Press, 2014) Tarhan, Özgür; Tarhan, Enver; Harsa, ŞebnemAlpha-lactalbumin (α-la) is one of the major proteins in whey. When partially hydrolysed with Bacillus licheniformis protease, it produces nanotubular structures in the presence of calcium ions by a self-assembly process. This study presents investigation of α-la protein structure during hydrolysis and nanotube formation using optical spectroscopy. Before spectroscopic measurements, nanotubes were examined with microscopy. The observed α-la nanotubes (α-LaNTs) were in the form of regular hollo strands with a diameter of about 20 nm and the average length of 1 μm. Amide and backbone vibration bands of the Raman spectra displayed remarkable conformational changes in α and β domains in the protein structure during nanotube growth. This was confirmed by the Fourier-transform infrared (FTIR) spectroscopy data. Also, FTIR analysis revealed certain bands at calcium (Ca++) binding sites of COO- groups in hydrolysed protein. These sites might be critical in nanotube elongation.Article Citation - WoS: 11Citation - Scopus: 9Biophysical Evaluation of Physiological Effects of Gilthead Sea Bream (sparus Aurata) Farming Using Ftir Spectroscopy(Elsevier Ltd., 2014) Ceylan, Çağatay; Tanrıkul, Tansel; Özgener, HüseyinSparus aurata is one of the two most important cultured fish species in the Mediterranean region. The present work investigates the effects of culturing in S. aurata liver tissue at the molecular level using Fourier Transform Infrared (FTIR) spectroscopy. FTIR spectroscopy revealed dramatic differences between the wild and aquacultured fish liver cells, which mainly indicated that the level of glycogen increased in the aquacultured samples and the protein/lipid ratio decreased by 42.29% indicating that triglycerides and cholesterol esters increased and the protein content decreased in the aquacultured samples. The 15.99% increase in the level of unsaturation indicated elevated lipid peroxidation. Structural/organisational changes in the nucleic acids along with increased transcriptional status of the liver tissue cells were observed in the cultured fish tissue. All these results indicated that culturing induces significant changes in fish physiology. In addition FTIR spectroscopy is a promising method to monitor the physiological changes in fish physiology.Article Citation - WoS: 55Citation - Scopus: 59Prediction of Various Chemical Parameters of Olive Oils With Fourier Transform Infrared Spectroscopy(Academic Press Inc., 2015) Uncu, Oğuz; Özen, BanuVibrational spectroscopic techniques offer advantages such as rapid and accurate measurements with minimum sample preparation and waste generation. In this study, it was aimed at determining some important quality parameters (oxidative stability, colour pigments, fatty acid profile and phenolic composition) of olive oils by Fourier transform infrared spectroscopy as one of the vibrational spectroscopic methods. Partial least square calibration models were constructed in order to reveal any correlation between quality parameters and spectral data. Regression coefficients for developed models showed that oxidative stability (0.99), chlorophyll content (0.98), some major fatty acids (palmitic (0.87), oleic (0.94), and linoleic acids (0.97), saturated (0.91), monounsaturated (0.94) and polyunsaturated fatty acids (0.97)), hydroxytyrosol as a phenolic compound (0.97) and total phenolic content (0.99) were predicted successfully. Variable influence on the projection values indicated that palmitic, vanillic and cinnamic acids and hydroxytyrosol are the most significant contributors to oxidative stability of olive oils. © 2015 Elsevier Ltd.